how long is a second?

R

Richard Sutcliffe

Well-known member
I also posted this on the cow a while ago but let the thread die because I was away.

we shot an athletics race recently and I've run into something unexpected. In post, I'm cutting the footage (PAL 50fps) and the race length (ie time on the clock at the end) is 4 seconds less than the duration of the race recorded by the camera (I've cut the clip at the gun going off and the winner crossing the line to get as close as possible to the track timing.

No gen-lock or sync used on the cameras and unfortunately only 1 camera recoded the entire race without buttoning off so I have no other cameras to compare against.

some drift is to be expected but 4 seconds out after 4 minutes seems VERY high to me.

Is this a problem with my camera, anyone else experienced anything similar?

I'm going to put my camera against the clock now for 4 minutes and see what clip duration I get.
 
Sound like "Kiwi" time to me. sorry couldn't help myself.
Check your frame rate against your sequence settings, also what cam was it shot on and what edit platform are you using.

Cheers
TomK
olinevideo.com.au
 
Even 29.97 drop frame only loses something like two frames a minute, that's pretty extreme. There's something up other than frame rate. Can you see a running clock in the footage? If so, you could watch it and match with time code or a stop watch. But experimenting like you already are is probably the best way. Be sure to post once it's figured out.
 
Thanks but, we are PAL so no drop frame, I shot 720p/50 and am editing 720p/50

Shot HPX502 edit FCP 6.0.5.

Far from new to this game but this the first time we've shot anything so accurately timed. I'm putting my camera against the clock now - will post the results soon. Anyone willing to do the same?
 
Okay, 5:30:32 on the stopwatch, 5:30:10 on the clip duration and I pushed start and stop manually so that accounts the discrepancy - not the camera basically.
 
Looking at the master clip of the race in P2CMS. Ran freerun TOD TC.

gun at 09:20:11:01 winner crossed line 09:24:04:24. My calculation = 3min 53 23fr

On the timeline placing a cut at the same frame -gun going off and crossing the line - clip duration = 3:54:25fr

Official timing clock shows 03:50:63

My head hurts
 
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